GPT-5.6 Becomes the Preferred AI Model in Microsoft 365 Copilot

Microsoft is making GPT-5.6 the preferred model in Microsoft 365 Copilot, bringing OpenAI’s latest model family to Word, Excel, PowerPoint, Copilot Chat and Cowork. The upgrade promises better documents, deeper data analysis and more capable cross-functional AI workflows.

OpenAI’s GPT-5.6 is becoming the preferred model in Microsoft 365 Copilot, bringing the latest generation of OpenAI intelligence directly into Word, Excel, PowerPoint, Copilot Chat and Cowork.

The update is designed to improve the quality of work produced through Copilot while reducing the amount of prompting and manual refinement required from users. It also strengthens Microsoft 365 Copilot’s ability to support more complex assignments spanning multiple applications and business functions.

For organisations already using Microsoft 365, the announcement means GPT-5.6 capabilities can become part of familiar workplace applications rather than requiring users to adopt a separate AI platform.

What does “preferred model” mean?

Microsoft 365 Copilot can use different AI models depending on the task. Designating GPT-5.6 as the preferred model means Microsoft is positioning it as the principal choice for a broad range of Copilot experiences.

Users will not necessarily need to understand which model should be used for every request. Copilot can apply GPT-5.6 within the existing Microsoft 365 experience to help users create, analyse and collaborate.

The announcement does not mean that GPT-5.6 is the only model Microsoft can use. Microsoft has been developing a multi-model AI strategy in which different models can be selected according to their performance, cost and suitability for a particular workload.

What GPT-5.6 brings to Microsoft 365

GPT-5.6 is OpenAI’s latest model family, comprising the flagship Sol model, the balanced Terra model and the faster, lower-cost Luna model. OpenAI has designed the family to produce more useful work from each token while providing additional capability for demanding tasks.

Within Microsoft 365 Copilot, the practical value of the upgrade is expected to appear in four areas:

Higher-quality business documents that require fewer revision cycles
More capable analysis of spreadsheets and organisational data
Better-designed presentations created with less detailed guidance
Stronger execution of complex work involving several people, applications or departments

These improvements could help Microsoft move Copilot beyond individual productivity assistance and towards more complete workplace workflows.

More effective drafting and editing in Word

In Microsoft Word, GPT-5.6 can help users draft, edit and refine documents with fewer rounds of prompting. This may be valuable for reports, proposals, policies, executive briefings and other documents that require a clear structure and professional tone.

A user could provide an objective, source material and an existing template, then ask Copilot to create a first draft. GPT-5.6’s stronger understanding of context and professional work may help it organise the content more effectively and follow the requested format more closely.

Potential uses include:

Converting meeting notes into a structured report
Rewriting technical information for an executive audience
Creating a proposal from several reference documents
Improving the structure and consistency of a lengthy document
Adapting content to match an organisation’s preferred style

Human review will remain important, especially for legal documents, policies, contracts and material containing financial or regulatory claims.

Deeper analysis in Excel

Microsoft says GPT-5.6 will support deeper analysis in Excel while using tokens more efficiently. This could help users move more quickly from raw figures to insights without needing advanced spreadsheet or data-analysis skills.

Copilot could assist with tasks such as:

Identifying trends and exceptions in business data
Explaining changes in revenue, costs or operational performance
Creating and checking formulas
Producing charts and management summaries
Comparing actual results with forecasts or targets
Building structured financial and operational models

GPT-5.6’s efficiency may be particularly important for large spreadsheets and multi-step analysis. Using fewer tokens and requiring fewer interactions can improve completion time and reduce the overall cost of AI-assisted work.

Users should still verify formulas, calculations and source data before using Copilot’s findings to make financial or operational decisions.

Copilot Chat gains a more capable foundation

GPT-5.6 will also support Copilot Chat, giving users access to the model through a conversational interface within Microsoft 365.

Copilot Chat can help people locate information, summarise workplace content, explore ideas and prepare outputs without moving between multiple applications. With GPT-5.6, these conversations may require less detailed prompting and produce results that are closer to a usable final version.

The value of Copilot Chat increases when it can work with organisational context, including documents, emails, meetings and other permitted Microsoft 365 data. This allows the assistant to respond using information relevant to the organisation rather than relying only on general model knowledge.

Cowork targets complex cross-functional assignments

One of the most significant applications of GPT-5.6 may be Cowork, where the model can help users complete complex assignments that cross applications, information sources and functional teams.

For example, Cowork could potentially help a user gather source material, analyse supporting data, prepare a written report and create a presentation as parts of one coordinated assignment.

Possible workplace scenarios include:

Combining sales, financial and operational information into a quarterly business review
Preparing a customer proposal using CRM data, meeting notes and previous documents
Creating an executive briefing from emails, spreadsheets and project updates
Coordinating research and deliverables across several business functions
Turning a collection of source files into a finished report and presentation

This moves Copilot closer to an AI work partner that can coordinate a series of related tasks rather than assisting with one document or application at a time.

Microsoft will access GPT-5.6 through the OpenAI API

Microsoft will use GPT-5.6 through the OpenAI API in addition to serving OpenAI models through its existing infrastructure. This provides Microsoft with another route for integrating OpenAI’s latest capabilities into Microsoft 365 products.

The arrangement also demonstrates the continuing importance of the partnership between Microsoft and OpenAI. Although Microsoft is expanding its wider model portfolio and developing its own AI capabilities, OpenAI’s flagship models remain central to key Copilot experiences.

What the upgrade means for Microsoft 365 customers

The GPT-5.6 upgrade should not be viewed simply as a chatbot receiving a more intelligent model. Its larger potential lies in improving the complete process of turning workplace information into usable results.

For Microsoft 365 customers, that could mean:

Less time spent rewriting or reformatting AI-generated content
Fewer prompts required to complete a task
More accurate and useful analysis of business information
Better consistency with organisational templates
More complex workflows completed within Microsoft 365

The actual business benefit will depend on how effectively organisations prepare their data, permissions, templates and working practices. A stronger model cannot correct poorly maintained source information or unclear ownership of business processes.

Governance becomes more important as Copilot does more

As Microsoft 365 Copilot becomes capable of completing broader assignments, organisations will need to strengthen their approach to AI governance.

Before expanding adoption, businesses should review:

Whether Microsoft 365 permissions accurately reflect who should access each document and data source
Which types of information employees may process through Copilot
When AI-generated work requires human approval
How outputs will be checked for factual and numerical accuracy
Whether sensitive prompts and generated files are handled appropriately
How the organisation will measure productivity, quality and return on investment

Permission management is particularly important because Copilot’s responses can draw on information a user is authorised to access. Excessive or outdated permissions may therefore expose information more easily than intended.

A significant step in the evolution of Microsoft 365 Copilot

Making GPT-5.6 the preferred model gives Microsoft 365 Copilot a stronger foundation for writing, analysis, presentation design and agentic work.

The update also shows how quickly frontier AI capabilities are moving into everyday business software. Employees may experience the benefits of a new model through the applications they already use, often without needing to select or manage the underlying technology themselves.

The most important test will be whether GPT-5.6 produces outputs that require materially less correction and supervision. If it can reduce revision cycles while improving the quality of complex work, the upgrade could make Microsoft 365 Copilot substantially more valuable to organisations.